Postgrey - how to add sending server to whitelist to disable greylisting

Solution 1:

You performed the right steps, adding to whitelist_clients. It is better to create a new file whitelist_clients.local, which is not modified while upgrading the postgrey package and is also read by postgrey. Then, restart postgrey.

But, due to a bug in the Debian postgrey init script, postgrey is not actually being restarted by running service postgrey restart (even stopping it is broken). Either restart the whole machine, or kill the postgrey process manually and start it again (using service postgrey start).

The issue is told to be fixed in June 2014 and restart is hopefully working in future Debian/Ubuntu releases.